Method for the production of N-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides and new intermediate products

ABSTRACT

The invention relates to a process for preparing N-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides in which, in a first step, 2-amino-4,5-difluoro-benzonitrile is reacted with sulphonyl halides in the presence of an acid acceptor and in the presence of a diluent at temperatures between 0° C. and 150° C. and, in a second step, the N-(2-cyano-4,5-difluoro-phenyl)-sulphon-amides and/or N-(2-cyano-4,5-difluoro-phenyl)-sulphonamides obtained in the first step are as pure substances or as mixtures with ammonia in the presence of a diluent reacted at a temperature between 100° C. and 200° C. The invention furthermore relates to novel intermediates of the process.

This application is the National Stage Application of PCT/EP98/04324,which claims priority from German Application 197 31 783.9 filed Jul.24, 1997.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a novel process for preparingN-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides, which are known asintermediates in the preparation of herbicides, to novelN-(2-cyano-4,5-difluoro-phenyl)-sulphonamides andN-(2-cyano-4,5-difluoro-phenyl)-sulphonimides as intermediates for thisprocess and to processes for their preparation.

BACKGROUND OF THE INVENTION

It is known that certainN-(5-amino-2-cyano-4-fluoro-phenyl)-alkanesulphonamides, such as, forexample, N-(5-amino-2-cyano-4-fluoro-phenyl)-methanesulphonamide, areobtained when corresponding halogenated benzene derivatives, such as,for example, 1-amino-4-cyano-2,5-difluoro-benzene, are heated withalkanesulphonamides, such as, for example, methanesulphonamide, in thepresence of an acid binder, such as, for example, potassium carbonate,and in the presence of a diluent, such as, for example,N-methyl-pyrrolidone (see EP-A-648772). However, this process affordsthe desired products in unsatisfactory yields. Accordingly, there is aneed for a more favourable preparation process forN-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides.

DETAILED DESCRIPTION OF THE INVENTION

It has now been found thatN-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides of the general formula(I)

in which

R represents in each case optionally substituted alkyl, alkenyl,alkinyl, cyclo-alkyl, cycloalkylalkyl, aryl, arylalkyl, heterocyclyl orheterocyclylalkyl

are obtained in high yields and in very good quality when, in a firststep, 2-amino-4,5-difluoro-benzonitrile of the formula (II)

 is reacted with sulphonyl halides of the general formula (III)

X—SO₂—R  (III)

in which

R is as defined above and

X represents halogen

in the presence of an acid acceptor and in the presence of a diluent attemperatures between 0° C. and 150° C.

and the resulting N-(2-cyano-4,5-difluoro-phenyl)-sulphonamideintermediates of the general formula (IV) and/orN-(2-cyano-4,5-difluoro-phenyl)-sulphonimide intermediates of thegeneral formula (V)

 in which

R is as defined above

are reacted as pure substances or as mixtures in a second step withammonia in the presence of a diluent at temperatures between 100° and200° C.

Surprisingly, the N-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides ofthe general formula (I) can be obtained by the process according to theinvention in a relatively simple manner in high yields and in very goodquality, and a pure end product can be prepared via a mixture ofintermediates. The intermediates of the formulae (IV) and (V) can beobtained as mixtures in virtually quantitative yield.

The main advantage of the process according to the invention is the factthat the use of relatively expensive 2,4,5-trifluoro-benzonitrile can bedispensed with, and the problematic exchange of a fluorine substituentfor a sulphonylamino group is not necessary.

The compound 2-amino-4,5-difluoro-benzonitrile of the formula (II) to beused as starting material has not yet been disclosed in the literature;as a novel substance, it also forms part of the subject-matter of thepresent invention.

The novel compound of the formula (II) is obtained when4,5-difluoro-2-nitro-benzonitrile of the formula (VI)

is reacted with a reducing agent which is customary for convertingaromatic nitro compounds into the corresponding amino compounds, suchas, for example, (a) hydrogen in the presence of a catalyst such as, forexample, platinum or palladium (where the two last-mentioned compoundsare, if appropriate, “poisoned” and supported on a carrier, such as, forexample, activated carbon or barium sulphate), in the presence of adiluent, such as, for example, tetrahydrofuran or dioxane, or (b) metalsor metal salts, such as, for example, tin, tin(II) chloride, iron(powder) in the presence of an acid, such as, for example, hydrochloricacid or acetic acid, and, if appropriate, additionally in the presenceof a diluent, such as, for example, methanol or ethanol, at temperaturesbetween 0° C. and 150° C., preferably between 10° C. and 100° C. (cf.the Preparation Examples).

The intermediates of the formulae (IV) and (V) are not yet known fromthe literature; as novel substances, they also form part of thesubject-matter of the present invention.

The 4,5-difluoro-2-nitro-benzonitrile of the formula (VI) required asprecursor is already known (see JP 07070041 - cited in Chem. Abstracts123:111678). According to the patent literature cited,4,5-difluoro-2-nitro-benzonitrile can be prepared by reaction of2-bromo-4,5-difluoro-nitrobenzene with copper(I) cyanide inN,N-dimethyl-formamide.

However, the compound of the formula (VI) is also obtained when3,4-difluoro-benzonitrile is reacted with nitric acid, if appropriate inthe presence of sulphuric acid, at temperatures between −10° C. and +30°C. (cf. the Preparation Examples).

Surprisingly, this nitration proceeds in a very uniform manner(regioselectively), and hydrolysis of the cyano group, which is to beexpected under the nitration conditions, only occurs to a very lowextent.

The formula (III) provides a general definition of the sulphonyl halidesfurther to be used as starting materials in the process according to theinvention for preparingN-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides of the general formula(I).

Preferred meanings in the formulae (I), (III), (IV) and (V) are:

R represents in each case optionally halogen-substituted alkyl, alkenylor alkinyl having in each case up to 6 carbon atoms, represents in eachcase optionally halogen- or C₁-C₄-alkyl-substituted cycloalkyl orcycloalkylalkyl having in each case 3 to 6 carbon atoms in thecycloalkyl group and, if appropriate, 1 to 4 carbon atoms in the alkylmoiety, represents in each case optionally nitro-, cyano-, halogen-,C₁-C₄-alkyl-, C₁-C₄-halogenoalkyl-, C₁-C₄-alkoxy-, C₁-C₄-halogenoalkoxy-or C₁-C₄-alkoxy-carbonyl-substituted aryl or arylalkyl having 6 or 10carbon atoms in the aryl group and, if appropriate, 1 to 4 carbon atomsin the alkyl moiety, or represents in each case optionally cyano-,halogen-, C₁-C₄-alkyl-, C₁-C₄-halogenoalkyl-. C₁-C₄-alkoxy- orC₁-C₄-halogenoalkoxy-substituted heterocyclyl or heterocyclylalkylhaving in each case 3 to 5 carbon atoms and 1 or 2 nitrogen atoms and/orone oxygen or sulphur atom in the heterocyclyl group and, ifappropriate, 1 to 4 carbon atoms in the alkyl moiety, and

x represents fluorine, chlorine or bromine.

Particularly preferred meanings in the above formulae are:

R represents in each case optionally fluorine- or chlorine-substitutedmethyl, ethyl, n- or i -propyl, n-, i-, s- or t-butyl, ethenyl,propenyl, butenyl, ethinyl, propinyl or butinyl, represents in each caseoptionally fluorine-, chlorine-, methyl- or ethyl-substitutedcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl,cyclobutylmethyl, cyclopentylmethyl or cyclohexyl-methyl, represents ineach case optionally nitro-, cyano-, fluorine-, chlorine-, bromine-,methyl-, ethyl-, n- or i-propyl-, n-, i-, s- or t-butyl-, tri-fluoromethyl-, methoxy-, ethoxy-, n- or i-propoxy-, n-, i-, s- ort-butoxy-, difluoromethoxy-, trifluoromethoxy-, methoxycarbonyl-,ethoxycarbonyl-, n- or i-propoxycarbonyl-substituted phenyl or benzyl,or represents in each case optionally cyano-, fluorine-, chlorine-,bromine-, methyl-, ethyl-, n- or i-propyl-, n-, i-, s- or t-butyl-,trifluoromethyl-, methoxy-, ethoxy-, n- or i-propoxy-, n-, i-, s- ort-butoxy-, difluoromethoxy- or trifluoromethoxy-sub-situatedheterocyclyl from the group consisting of furyl, thienyl, oxazolyl,isoxazolyl, pyrazolyl, pyridinyl and pyrimidinyl, and

x represents chlorine.

The starting materials of the formula (III) are known chemicals forsynthesis.

The first step of the process according to the invention for preparingN-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides of the general formula(I) is carried out using an acid acceptor. Suitable acid acceptors are,in general, the customary inorganic or organic bases or acid acceptors.These preferably include alkali metal or alkaline earth metal acetates,amides, carbonates, bicarbonates, hydrides, hydroxides or alkoxides,such as, for example, sodium acetate, potassium acetate or calciumacetate, lithium amide, sodium amide, potassium amide or calcium amide,sodium carbonate, potassium carbonate or calcium carbonate, sodiumbicarbonate, potassium bicarbonate or calcium bicarbonate, lithiumhydride, sodium hydride, potassium hydride or calcium hydride, lithiumhydroxide, sodium hydroxide, potassium hydroxide or calcium hydroxide,sodium methoxide, ethoxide, n- or -i-propoxide, n-, i-, s- or t-butoxideor potassium methoxide, ethoxide, n- or i-propoxide, n-, i-, s- ort-butoxide; furthermore also basic organic nitrogen compounds, such as,for example, trimethylamine, triethylamine, tripropylamine,tributylamine, ethyl-diisopropylamine, N,N-dimethyl-cyclohexylamine,dicyclohexylamine, ethyl-dicyclohexylamine, N,N-dimethyl-aniline,N,N-dimethyl-benzylamine, pyridine, 2-methyl-, 3-methyl-, 4-methyl-,2,4-dimethyl-, 2,6-dimethyl-, 3,4-dimethyl- and 3,5-dimethyl-pyridine,5-ethyl-2-methyl-pyridine, 4-dimethylamino-pyridine,N-methyl-piperidine, 1,4-diazabicyclo[2.2.2]-octane (DABCO),1,5-diazabicyclo[4.3.0]-non-5-ene (DBN) or1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU).

Preferred acid acceptors are basic organic nitrogen compounds.

Suitable diluents for carrying out the first step of the processaccording to the invention are, especially, inert organic solvents.These include, in particular, aliphatic, alicyclic or aromatic,optionally halogenated hydrocarbons, such as, for example, benzine,benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleumether, hexane, cyclohexane, dichloromethane, chloroform, carbontetrachloride; ethers, such as diethyl ether, diisopropyl ether,dioxane, tetrahydrofuran or ethylene glycol dimethyl ether or ethyleneglycol diethyl ether; ketones, such as acetone, butanone or methylisobutyl ketone; nitriles, such as acetonitrile, propionitrile orbutyronitrile; amides, such as N,N-dimethylformamide,N,N-dimethylacetamide, N-methyl-formanilide, N-methyl-pyrrolidone orhexamethylphosphoric triamide; esters, such as methyl acetate or ethylacetate, sulphoxides, such as dimethyl sulphoxide.

Preferred diluents are aprotic polar organic solvents, in particularacetone or acetonitrile, or else basic organic nitrogen compounds, suchas pyridine or 5-ethyl-2-methyl-pyridine.

When carrying out the first step of the process according to theinvention, the reaction temperatures can be varied within a relativelywide range. In general, the first step is carried out at temperaturesbetween 0° C. and 150° C., preferably between 10° C. and 120° C.

The first step of the process according to the invention is generallycarried out under atmospheric pressure. However, it is also possible tocarry out the process according to the invention under elevated orreduced pressure—generally between 0.1 bar and 10 bar.

For carrying out the first step of the process according to theinvention, generally between 1 mol and 10 mol, preferably between 2 moland 5 mol, of sulphonyl halide of the general formula (III) and between1 mol and 10 mol, preferably between 2 mol and 5 mol, of acid acceptorare employed per mole of 2-amino-4,5-difluoro-benzonitrile of theformula (II).

In a preferred embodiment of the first step of the process according tothe invention, the 2-amino-4,5-difluoro-benzonitrile of the formula (II)is initially charged together with an acid acceptor and a diluent, andthe sulphonyl halide of the general formula (III) is then slowly meteredinto this mixture with stirring—and, if appropriate, with cooling. Thecomplete reaction mixture is then—if appropriate at elevatedtemperature—stirred until the reaction has ended.

The mixture of the intermediates of the formulae (IV) and (V) can beworked up in a customary manner. The mixture is, for example, stirredwith water or a dilute aqueous acid, the organic phase is separated off,the aqueous phase is, if appropriate, reextracted with an organicsolvent which is virtually water-miscible, such as, for example, ethylacetate, and the combined organic phases are dried and filtered. Toisolate the mixture of intermediates, the solvent is carefully distilledoff under reduced pressure from the filtrate.

The resulting mixtures of the intermediates of the formulae (IV) and (V)can advantageously be employed without any further purification for thereaction according to the second step of the process according to theinvention.

The second step of the process according to the invention is preferablycarried out using a diluent. Suitable diluents are, especially, inertorganic solvents. These include, in particular, aliphatic, alicyclic oraromatic, optionally halogenated hydrocarbons, such as, for example,benzine, benzene, toluene, xylene, chlorobenzene, dichlorobenzene,petroleum ether, hexane, cyclohexane, dichloromethane, chloroform,carbon tetrachloride; ethers, such as diethyl ether, diisopropyl ether,t-butyl methyl ether, t-pentyl methyl ether, dioxane, tetrahydrofuran orethylene glycol dimethyl ether or ethylene glycol diethyl ether;ketones, such as, acetone, butanone or methyl isobutyl ketone; nitriles,such as acetonitrile, propionitrile or butyronitrile; amides, such asN,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-formanilide,N-methyl-pyrrolidone or hexamethylphosphoric triamide; esters, such asmethyl acetate or ethyl acetate, sulphoxides, such as dimethylsulphoxide.

Preference is given to using, as diluents, aprotic polar organicsolvents, in particular diisopropyl ether, t-butyl methyl ether,t-pentyl methyl ether, tetrahydrofuran, dioxane, ethylene glycoldimethyl ether or ethylene glycol diethyl ether.

When carrying out the second step of the process according to theinvention, the reaction temperatures can be varied within a relativelywide range. In general, the second step is carried out at temperaturesbetween 50° C. and 200° C., preferably between 100° C. and 180° C.

The second step of the process according to the invention is generallycarried out in a closed reaction vessel (in particular in an autoclave)under elevated pressure, the pressure depending on the set temperatureand the solvent used.

For carrying out the second step of the process according to theinvention, generally between 1 and 100 mol, preferably between 5 and 50mol, of ammonia are employed per mole of the sum of the intermediates ofthe formulae (IV) and (V).

In a preferred embodiment of the second step of the process according tothe invention, the reaction components of the formula (IV) and/or (V)are mixed at room temperature (about 20° C.) with ammonia and a diluentand heated in a closed reaction vessel until the reaction has ended.

Work-up and isolation of the products of the formula (I) can be carriedout by customary methods. The reaction mixture is, for example, filteredafter cooling, and the solvent is carefully distilled off under reducedpressure from the filtrate. The product can be obtained in this manneras a residue, generally in good quality.

The compounds of the formula (I) preparable by the process according tothe invention can be employed as intermediates for preparingherbicidally active compounds (see EP-A-648749, EP-A-648772,WO-A-95/29158).

The intermediates of the formulae (IV) and (V) can also be used asprecursors for preparing herbicides (see EP-A 609734).

PREPARATION EXAMPLES Example 1

Step 1

15 g (130 mmol) of methanesulphonyl chloride are added dropwise withstirring to a mixture of 3.7 g (24 mmol) of2-amino-4,5-difluoro-benzonitrile, 5.0 g (33 mmol) of1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) and 50 ml of pyridine, and thereaction mixture is then heated at 50° C. for approximately one hour.The mixture is subsequently concentrated under water pump vacuum, theresidue is stirred with 100 ml of 20% strength hydrochloric acid and 10ml of ethyl acetate and the crystalline product is isolated byfiltration with suction.

This gives 3.3 g (44% of theory) of4,5-difluoro-2-(bis-methanesulphonyl-amino) -benzonitrile of meltingpoint 144° C.

Step 2

In a 100 ml autoclave, 2 ml of ammonia are condensed and 2.0 g (6.4mmol) of 4,5-difluoro-2-(bis-methanesulphonyl-amino)-benzonitrile and 40ml of tetrahydrofuran are added. The reaction mixture is then heated inthe closed autoclave at 150° C. for 15 hours. After cooling, the mixtureis filtered and the filtrate is concentrated under water pump vacuum.Washing with 2N hydrochloric acid and with water gives 0.50 g (34% oftheory) of N-(5-amino-2-cyano-4-fluoro-phenyl)-methanesulphonamide ofmelting point 235° C.

Example 2

Step 1

4.6 g (40 mmol) of methanesulphonyl chloride are added dropwise withstirring to a mixture of 1.54 g (10 mmol) of2-amino-4,5-difluoro-benzonitrile, 4.0 g (40 mmol) of triethylamine and50 ml of acetonitrile, and the complete reaction mixture is then heatedunder reflux for approximately one hour. After cooling, the mixture isstirred with 100 ml of ice-water for 30 minutes, the phases areseparated and the aqueous phase is reextracted with 50 ml of ethylacetate. The combined organic phases are washed with saturated aqueousammonium bicarbonate solution and then with water, dried using sodiumsulphate and filtered. The solvent is carefully distilled off from thefiltrate under water pump vacuum.

This gives 2.9 g of a mixture of 43% of4,5-difluoro-2-(bis-methyl-sulphonylamino)-benzonitrile and 57% of4,5-difluoro-2-methylsulphonylamino-benzonitrile (according to GC/MS) asresidue, corresponding to a quantitative overall yield.

Step 2

In a 100 ml autoclave, 4.5 ml of ammonia are condensed and the productmixture obtained according to step 2 (2.9 g) and 50 ml oftetrahydrofuran are added. The reaction mixture is then heated in theclosed autoclave at 150° C. for 15 hours. After cooling, the mixture isfiltered and the filtrate is concentrated under water pump vacuum.Washing with 2N hydrochloric acid and with water gives 1.0 g (44% oftheory) of N-(5-amino-2-cyano-4-fluoro-phenyl)-methanesulphonamide ofmelting point 235° C.

Example 3

Step 1

5.1 g (40 mmol) of ethanesulphonyl chloride are added dropwise withstirring to a mixture of 1.54 g (10 mmol) of2-amino-4,5-difluoro-benzonitrile, 4.0 g (40 mmol) of triethylamine and50 ml of acetonitrile, and the complete reaction mixture is then heatedunder reflux for approximately two hours. After cooling, the mixture isstirred with 100 ml of ice-water for 30 minutes, the phases areseparated and the aqueous phase is reextracted with 50 ml of ethylacetate. The combined organic phases are dried using sodium sulphate andfiltered. The solvent is carefully distilled off from the filtrate underwater pump vacuum.

This gives 3.0 g of a mixture of 67% of4,5-difluoro-2-(bis-ethyl-sulphonylamino) -benzonitrile and 33% of4,5-difluoro-2-ethylsulphonylamino-benzonitrile (according to GC/MS) asresidue, corresponding to a quantitative overall yield.

Step 2

In a 100 ml autoclave, 4 ml of ammonia are condensed and 3.0 g of theproduct mixture from Step 1 and 50 ml of tetrahydrofuran are added. Thereaction mixture is heated in the closed autoclave at 150° C. for 15hours and, after cooling, filtered. The filtrate is concentrated underwater pump vacuum, washed with 2N hydrochloric acid and with water anddried.

This gives 1.1 g (45% of theory of a 95.5% pure product) of4-amino-5-fluoro-2-ethylsulphonylamino-benzonitrile of melting point170° C.

Starting Material of the Formula (II) Example (II-1)

3.68 g (20 mmol) of 4,5-difluoro-2-nitro-benzonitrile are dissolved in40 ml of dioxane, and 300 mg of platinum on carbon (5%) are added. Thesuspension is subsequently stirred under hydrogen at from 20° C. to 25°C. until 1.45 litres of hydrogen have been taken up. The mixture is thenfiltered through silica gel and the filtrate is concentrated under waterpump vacuum. The residue is then worked up by column chromatography(silica gel, hexane/ethyl acetate).

This gives 2.19 g (72% of theory) of 2-amino-4,5-difluoro-benzonitrileof melting point 114° C. and, from another fraction 0.52 g (15% oftheory) of 2-amino-4, 5-difluoro-benzamide.

Example (II-2)

11.0 g (59 mmol) of 4,5-difluoro-2-nitro-benzonitrile are dissolved in175 ml of acetic acid (“glacial acetic acid”), and 20 g (358 mmol) ofiron (powder) are added a little at a time. During the addition, thereaction temperature is kept at from 40° C. to 50° C. by cooling using awater bath. The complete reaction mixture is then stirred at 50° C. foranother 3 hours. After cooling to room temperature, the mixture ispoured into 200 ml of ice-water. The mixture is extracted twice with 50ml of ethyl acetate each time, and the organic extract solutions arecombined, washed with saturated sodium bicarbonate solution and thenwith water, dried with sodium sulphate and filtered. The filtrate isconcentrated under water pump vacuum and the residue is worked up bycolumn chromatography (silica gel, hexane/ethyl acetate).

This gives 7.7 g (85% of theory) of 2-amino-4,5-difluoro-benzonitrile ofmelting point 114° C.

Starting Material of the Formula (VI) Example (VI-1)

A mixture of 40 ml of sulphuric acid (97% strength) and 30 ml of nitricacid (98% strength) is cooled to 0° C. 13.9 g (0.10 mol) of3,4-difluoro-benzonitrile are then added a little at a time such thatthe reaction temperature stays below 5° C. The complete reaction mixtureis stirred at from 5° C. to 10° C. for 5 hours and, after warming to 20°C., stirred for another 2 hours. The mixture is subsequently poured onto400 g of ice, and the crystalline product is isolated by filtration withsuction and taken up in 20 ml of methylene chloride. The aqueous phaseis reextracted twice using 30 ml of methylene chloride each time. Theorganic phases are combined, washed with saturated sodium bicarbonatesolution and with water, dried with sodium sulphate and filtered. Thesolvent is carefully distilled off from the filtrate under water pumpvacuum.

This gives 10.2 g (55% of theory) of 4,5-difluoro-2-nitro-benzonitrileof melting point 75° C.

What is claimed is:
 1. A process for preparing aN-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamide of the formula (I)

wherein R represents in each case unsubstituted or substituted alkyl,alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl,heterocyclyl or heterocyclylalkyl, comprising the steps of: a) reactinga 2-amino-4,5-difluoro-benzonitrile of the formula (II)

 with a sulphonyl halide of the formula (III) X—SO₂—R  (III)  wherein Ris as defined above and X represents halogen  in the presence of an acidacceptor and in the presence of a diluent at a temperature between 0° C.and 150° C.; and b) reacting aN-(2-cyano-4,5-difluoro-phenyl)sulphonamide of the formula (IV) obtainedin step a)

 wherein R is as defined above with ammonia in the presence of a diluentat a temperature between 100° C. and 200° C.
 2. The process of claim 1,wherein R represents in each case unsubstituted or halogen-substitutedalkyl, alkenyl or alkynyl having in each case up to 6 carbon atoms,represents in each case unsubstituted or halogen- orC₁-C₄-alkyl-substituted cycloalkyl or cycloalkylalkyl having in eachcase 3 to 6 carbon atoms in the cyclo-alkyl group and 1 to 4 carbonatoms in the alkyl moiety, represents in each case unsubstituted ornitro-, cyano-, halogen-, C₁-C₄-alkyl-, C₁-C₄-halogenoalkyl-,C₁-C₄-alkoxy-, C₁-C₄-halogenoalkoxy- orC₁-C₄-alkoxy-carbonyl-substituted aryl or arylalkyl having 6 or 10carbon atoms in the aryl group and 1 to 4 carbon atoms in the alkylmoiety, or represents in each case unsubstituted or cyano-, halogen-,C₁-C₄-alkyl-, C₁-C₄-halogenoalkyl-, C₁-C₄-alkoxy- orC₁-C₄-halogenoalkoxy-substituted heterocyclyl or heterocyclylalkylhaving in each case 3 to 5 carbon atoms and 0, 1 or 2 nitrogen atoms andzero or one oxygen or sulphur atom in the heterocyclyl group and 1 to 4carbon atoms in the alkyl moiety, and X represents fluorine, chlorine orbromine.
 3. The process of claim 2, wherein R represents in each caseunsubstituted or fluorine- or chlorine-substituted methyl, ethyl, n- ori-propyl, n-, i-, s- or t-butyl, ethenyl, propenyl, butenyl, ethinyl,propinyl or butinyl, represents in each case unsubstituted or fluorine-,chlorine-, methyl- or ethyl-substituted cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclobutylmethyl,cyclopentylmethyl or cyclohexylmethyl, represents in each caseunsubstituted or nitro-, cyano-, fluorine-, chlorine-, bromine-,methyl-, ethyl-, n- or i-propyl-, n-, i-, s- or t-butyl-,trifluoromethyl-, methoxy-, ethoxy-, n- or i-propoxy-, n-, i-, s- ort-butoxy-, difluoromethoxy-, trifluoromethoxy-, methoxycarbonyl-,ethoxycarbonyl-, n- or i-propoxycarbonyl-substituted phenyl or benzyl,or represents in each case unsubstituted or cyano-, fluorine-,chlorine-, bromine-, methyl-, ethyl-, n- or i-propyl-, n-, i-, s- ort-butyl-, trifluoromethyl-, methoxy-, ethoxy-, n- or i-propoxy-, n-, i-,s- or t-butoxy-, difluoromethoxy- or trifluoromethoxy-substitutedhetero-cyclyl from the group consisting of furyl, thienyl, oxazolyl,isoxazolyl, pyrazolyl, pyridinyl and pyrimidinyl, and X representschlorine.
 4. The process of claim 1, wherein the acid acceptor is abasic organic nitrogen compound.
 5. The process of claim 1, wherein thediluent in step a) is selected from the group consisting of acetone andacetonitrile and the diluent in step b) is selected from the groupconsisting of pyridine and 5-ethyl-2-methyl-pyridine.
 6. The process ofclaim 1 wherein in step b) aN-(2-cyano-4,5-difluoro-phenyl)-sulphonimide of the formula (V)

wherein R represents in each case unsubstituted or substituted alkyl,alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl,heterocyclyl or heterocyclylalkyl, is added to the reaction mixture. 7.The process of claim 2 wherein the acid acceptor is a basic organicnitrogen compound.
 8. The process of claim 3 wherein the acid acceptoris a basic organic nitrogen compound.
 9. The process of claim 2 whereinthe diluent in step a) is selected from the group consisting of acetoneand acetonitrile and the diluent in step b is selected from the groupconsisting of pyridine and 5-ethyl-2-methyl-pyridine.
 10. The process ofclaim 3 wherein the diluent in step a) is selected from the groupconsisting of acetone and acetonitrile and the diluent in step b isselected from the group consisting of pyridine and5-ethyl-2-methyl-pyridine.
 11. The process of claim 4 wherein thediluent in step a) is selected from the group consisting of acetone andacetonitrile and the diluent in step b is selected from the groupconsisting of pyridine and 5-ethyl-2-methyl-pyridine.
 12. AN-(2-cyano-4,5-difluoro-phenyl)-sulphonamide of the general formula (IV)

wherein R is as defined in claim
 2. 13. AN-(2-cyano-4,5-difluoro-phenyl)-sulphonamide of the general formula (IV)

wherein R is as defined in claim
 3. 14. AN-(2-cyano-4,5-difluoro-phenyl)-sulphonimide of the general formula (V)

wherein R is as defined in claim
 2. 15. AN-(2-cyano-4,5-difluoro-phenyl)-sulphonimide of the general formula

wherein R is as defined in claim
 3. 16. AN-(2-cyano-4,5-difluoro-phenyl)-sulphonimide of the formula (IV)

wherein R is as defined in claim
 1. 17. AN-(2-cyano-4,5-difluoro-phenyl)-sulphonimide of the general formula (V)

wherein R is as defined in claim 1.